As a backlight of a liquid crystal display device, an illumination device using a combination of light-emitting elements such as light-emitting diodes (LEDs) and a wavelength conversion member comprising a fluorescent material, etc., is used. For example, an illumination device comprising a light-emitting element package including a number of light-emitting chips and a quantum dot sealed package provided above the light-emitting element package in the direction of light emission is disclosed. The illumination device converts a wavelength of light emitted from the light-emitting chips and emits the wavelength-converted light.
A quantum dot (light-emitting material), which is a wavelength conversion material, generally emits light in all directions. Therefore, part of light emitted from quantum dots is directed to light-emitting chips, which may result in a decrease in light use efficiency.